Track morphology in SiO quartz irradiated with swift heavy ions; Thickness and edge effects

Ishikawa, Norito   ; Taguchi, Tomitsugu*; Ogawa, Hiroaki  ; Toimil-Molares, M. E.*; Trautmann, C.*

Crystalline SiO quartz samples were irradiated with 1.64 GeV and 200 MeV Au ions, and the irradiation-induced nanostructures originating from ion track formation were examined using transmission electron microscopy. The analysis revealed not only homogeneous amorphous ion tracks but also tracks with a concentric core-halo structure, characterized by a low-density core along the ion path surrounded by a damaged halo region. This type of track was found exclusively in sample regions thinner than 50 nm, suggesting that a thin sample is the prerequisite for the formation of such low-density track cores. Additionally, pitted tracks with a crater-like structure were identified at the sample edges. These findings are discussed in terms of surface phenomena, such as electronic sputtering as well as the role of sample thickness and edge effects, emphasizing the critical influence of sample geometry on the formation of these complex nanostructures.